1. Field of the Invention
The invention relates to an image-capturing device, and more particularly, to an image-capturing device capable of automatically calibrating parameters of projection frames projected by a projection device.
2. Description of Related Art
With the progress in science and technology, the applications of infrared interactive projection system have gradually been increased, for example, electronic whiteboards and video games (such as Wii) are commonly used in daily life. In general, during the calibration between a projection device and an image-capturing device in the infrared interactive projection system is performed, for example, the user uses an infrared touch pen to touch some specific areas on the projection screen, such that the infrared interactive projection system may calculate the size and the resolution of the current projected image according to the touching behavior of touching these specific areas with the infrared touch pen, thereby adjusting the image-capturing device for the detection of a touch location. However, since the above-described calibration operation is performed by a manual approach and potentially due to the inaccurate touching behavior on the specific areas from the user, the infrared interactive projection system may generate errors in the operation for calculating the size and the resolution of the current projected image, thereby causing an inaccurate calibration result.
Taiwan Patent Publication No. 201020862 discloses a human-machine interactive manipulation system including a projector, an infrared emitting unit, an image-capturing unit and a processing unit. The projector produces a projection surface, and the infrared emitting unit generates a light spot onto the projection surface. The image-capturing unit is disposed with a filter for filtering out the visible light to obtain a distinct captured image. The processing unit is electrically connected with the projector and the image-capturing unit to perform the light spot detection for captured image information, so as to obtain the light spot location of the captured image information. The processing unit further includes a calibration unit for providing at least one calibration point on the projection surface and calculating location calibration parameters according to the calibration point location on the projection surface and the light spot location on the captured image information.
Taiwan Issued Patent No. 578031 discloses a projection system including a projector, an image-capturing device and a data processor. A light source of the projector is split into a visible light and an invisible light via a beam splitter. A picture image of the data processor is generated after the visible light part is modulated by a second imaging element, and a particular pattern is generated after the invisible light part is modulated by a first imaging element. The modulated visible light and the modulated invisible light are collected by a prism to form a light beam, and the light beam is projected onto the screen through a lens. The image-capturing device is utilized to sense the invisible light, and the particular pattern formed by the first imaging element is for providing the image-capturing device to capture variant patterns at different time points, so as to serve as the basis for calculating the movement direction and the movement amount of a cursor.
U.S. Patent Publication No. 2011/0169778 discloses an interactive projection system including a projection unit, a sensor and a computing device. The sensor with a photosensitive element may be utilized to detect the infrared light. When the projection system is calibrated, firstly, a calibration image is projected onto the screen, and the calibration image has calibration points at different locations respectively. The user uses a light stylus to emit the infrared light to each calibration point, in order for the infrared light to be reflected to the sensor. The sensor then may obtain each of the calibration points corresponding to the locations of the screen. The computing device receives the location information of the calibration points and converts them into coordinates, and adjusts the image outputted from the projection unit according to the coordinates.
U.S. Patent Publication No. 2003/0210230 discloses an invisible beam pointer system including a display screen, a sensor, a projector coupled to the sensor and an infrared pointer device. The projector may be connected with a processor to receive information. When the projector projects out an image frame, the user may drive the infrared pointer device to emit an infrared light to a certain location. The infrared light is reflected by the screen and received by the sensor, so as to obtain coordinate information of the location. After the coordinate information is transmitted to the projector, the image processor in the projector modifies the original image frame to another frame according to the coordinate information, thereby projecting another frame to the screen, such that the pre-calibration system may not be required.